Fuse cut-out



R. S. BENNETT FUSE CUT-OUT Filed March l5, 1936 Dec. 29, 1936.

Inventor: Ralph S. Bennett bg His ttorrwe Patented Dec. 29, 1936` UNITEDSTATES PATENT OEE-ICE I' 2,066,172 y FUSE cU'r-ou'i` Ralph S. Bennett,Pittsfield, Massi., assign'or to General Electric Company, avcorporation New York ofv Application March 13, 1936, serial No. 68,701

10 Claims.

The present invention relates to electric fuse cutoutsv and an object ofthe invention is the provision of an improved arrangement for mountingthe fuse holder of an expulsion fuse in a cutout to prevent impairmentof the operating parts and supporting structure of the cutout uponoperation of the fuse.

A further object of the invention is to improve type disclosed in thecopending application of Benjamin R. Hermann, Serial No. 65,994, ledFebruary 2'7, 1936, and assigned to the assignee of the presentinvention.

Other objects and the details of the construction and operation of anillustrative example of an enclosed fuse cutout embodying the presentinvention willy become apparent from the following description taken inconjunction with the accompanying drawing in which Fig. 1 is a`sectional side elevation of an enclosed fuse cutout showing the partsthereof in the positions they assume when the fuse unit is latched inits normal connected position and the fuse link is intact, and Fig. 2 lsa sectional side elevation of the cutout showing the parts in thepositions which they assume immediately after operation of the fuse.

Referring to the drawing, I designates a housing of porcelain or similarinsulating material having an open front and bottom and formed with anelectric creepage barrier I0' on its rear wall. A pair of stationarycontacts II and I2 are mounted in the housing respectively on oppositesides of barrier I0' and are adapted to have line, conductors fastenedthereto. A removable cover I3 is provided for the open front of thehousing and is arranged to be mounted on' the fuse unit I4 of the cutoutby means of projections or bosses I5 and I6 of insulating materialformed integrally with the cover and having `openings I5 and I6Qfsumcient size to provide `nected to contact cap I8 and the lower endcon,

Vnected to a conductor 2li extending out from the bottom of the fuseholder.

When the fuse unit I4 is in its normal connected position illustrated inFig.' l, contact cap I8 isarranged to engage a contact linger 2l carriedby the upper stationary contact I I and is backed up by a spring strip22 to provide the desired contact pressure. The contact finger isformed-with a downwardly facing concave seat 23 which serves as a latchto prevent outward swinging ofthe upper. endy of the fuse. Also,

(Cl. Zoll-114) when the fuse is in its normal connected position, coverI3, which is carried by the fuse holder I1, is arranged to close theopen front of housing I0. As will be seen from the drawing, the frontrim of the housing is provided with a flanged recess 24 into which therim of the cover is arranged to seat, as indicated at 25, insuiilciently close cooperative Erelation with the housing to prevent;the entrance of rain, snow and sleet to the interior of the housing andthus protect the parts of the cutout from damage by adverse4 weatherconditions. I y

In the exemplary embodiment illustrated, f use unit I4 and the cover I3carried thereby are sup.- ported in the housing I0 by means of a togglemechanism, one lever arm or element 26 of which is hingedly supported onhinge pins 2l carried by the housing, and the other arm or element 28 ofwhich is pivotally connected to the element 26 as indicated at 30. Atension spring 3| is connected between thetwo arms 26 and 28 and tendsto effect collapse of the'toggle mechanism. The details of theconstruction of this supporting toggle mechanism, which form no part ofthe present invention, are fully set forth in the previously referred tocopending application of Benjamin R. Hermann and hence there will bedescribed herein only sufilcient of the mechanism to insure a properunderstandingv of the present invention.

Toggle arm or element 26 is provided with slots 32 and 33 for theslidable engagement therewith of pins or studs 34 and 35, respectively,carried by a member 36 which is rigidly fastened to the fuse holder Il,thereby providing a pivotal and slidable connection between the fuse andthe toggle mechanism. As best shown in Fig. 2, member 36 is formedV withtwo arms 3l and 38 which have bores for the accommodation of the fuseholder. The rigid fastening of the member 36 to the fuse holderA iseffected by means of a screw 46 which engages openings in the arm 31 andis arranged to seat tightly in a groove 4I formed in one side of thefuse holder. Due to the loose fit of fuse holder Il within the openingsI5 and I6 of bosses I5 and I 6 on the cover, arms 31 and 38 of member 36are free to move to a limited extent between the boss I6 and a boss 42formed integrally With the cover and having a groove 43 in which thefuse holder may slide. e Arm 3l has a shoulder or abutment 44 andinterposed between this shoulder and the boss 42 is a compression spring45 which acts normally to maintain the cover in an elevated positionwith respect to the fuse holder andthe housing so that boss I6 contactswith arm 38 and the top of the cover seats ina goodweathertight mannerin the upper portion of recess24 as indicated at 25.

The hinged element or lever arm 26 of the fuse unit supporting togglemechanism is provided with a strap 46 and, as best shown in Fig..1,rthelower end of fuse holder I1 is latched normally in rigid engagement withthe strap by means of conductor 20 which is securely clamped to thestrap vto a contact 50 carried by element 28 of the i7og' gie. vThisstrip serves toinsure good electricy connection between that contact 5|!and the lower end of the fuse unit and to minimize current flow fthrough spring 3i and the elements of the toggle mechanism. L

To the back of the housing I0 there is secured a mounting bar, partiallyindicated at 5I, for the attachment of the cutout to a suitablesupporting structure, not shown. For manual operation of the cutout,cover I3 is provided with a handle 52 which may be grasped manually orengaged by a suitablefform of switch stick 'to swing the fuse unit anddoor assembly inwardly and outwardly about the hinge pins 21. i

When the cutout is closed, fuse unit I4 then, being connected betweenfixed contacts I I and I2 and door I3 closing the front of housing lIIIas illustrated in Fig. l, elements 26 and 28 of the supporting togglemechanism are Amaintained in the extended relation shown by the pressureof contact 50 ,againstthe bearing surface of contact I2. Under thesecircumstances spring 3i tends to effect collapse of the toggle mechanismas fully described in the previously referred to Hermann application, tocause outward movement of the fuse unit and door assembly. However, thecombined action of seat 23 and resilient backing strip 22 serves tolatch contact cap Il in. engagement with contact finger 2| and toprevent the upper end of this assembly from swinging outwardly abouthinge pins 21, while the toggle mechanism and the lower` end of the fuseunit and door assembly are latched by means of conductor 2li andclamping screw 41. The lower latch remains operative as long Nas thefuse link remains intact and the fuse unit is maintained thereby in itsinward position connected between fixed, contacts II and I2, theconnection at the upper end being through contact nnger 2i to contactcap I8 and at the lower end through contact 5II and strip 48-toconductor 2li. While the Vfuse unit is in this connected position,`cover I3 eiIectively closes the front of housing III, as previouslypointed out, to prevent the entrance oi' rain, sleet and snow to theinterior of the housing. If it is desired to open the cutout while thefuse link remains intact, this may be .done by 'grasping the handle 52on the cover, either manually'or by means of a; suitable switch stick,and pulling outwardly with sumcient force to disengage contact cap I8from seat 23 ofcontact finger 2i. The fuse holder, door and toggleassem- 4"bly can then be swung outwardly and downwardly as a unit to aposition at which the fuse unit is disconnected from the stationarycontacts. On the other hand, operation of fuse unit I4, when it is in.its normal connected position shown in Fig. l, results in automaticoperation of the cutout. Only suiiicient of the operation asis necessaryfor a full understanding of the present invention will be given herein,and reference may be had, if desired, to the previously' identiedHermann application for the details of the complete automatic operation.The first step in the operation of the'cutout is the expulso that thetoggle mechanism can become etlective to operate 'the cutout. At thesame time. the downwardly directed expulsion action of the fuse unitproduces a violent upwardly directed Vrecoil of 'the fuse holder sincethere is present usually some slack in the various connections oftheparts of the fuse supporting mechanism. In previous constructionswherein the door has been mounted on the Lfuse holder with little or noprovision made 'for relative movement between the fuse holder and thedoor, this recoil of the fuse holder, though partially absorbed by thefuse supporting structure and by the upper contact backing strip, stillhas been transmitted to the door to a sufiicient extent to produce aviolent upward movement of the door. As a result of this violent upwardmovement the upper rim of the door frequently strikes the front of theporcelain housing with sufiicient force to cause chipping or completebreaking of the door or the housing or both. An expedient for preventingsuch damage has been to provide a wide clearance between the door andthe housing at the point designated 2l onthe drawing. Under certainweather conditions,VV this wide clearance has permitted the entrance ofrain, sleet and snow into the housing. Inthe cutout constructed inaccordance with my present invention, the normal action of spring 4lmaintains the upper rim of the door in a re.la-`V tively closeweathertight relation with respect to the wall of `recess 24 so that itis impossible for rain, sleet and snow to enter the housing to impairthe parts of the cutout, while my improved' the fuse holder and the doorso that insuiilcient of the force oi the recoil is transmitted to thedoonto cause damage tio the housing or to the VVdoor itself.Furthermore, the cushioning action of the spring in combination with theinertia of the door produces a shock absorbing eii'ect which tends torelieve the fuse holder supporting structure of some of'the shock of therecoil. The positions of the parts of the cutout immediately subsequentto rupture of the fuse link are 'illustrated in Fig. 2 wherein the fuseholder is shown as having4 moved upwardly in the loose fitting openingsI5. and Ii' of thebosses I5 and II. respectively, of the cover, and arm3l is shown as having moved away from the boss Il while spring 45 isshown as being compressed between the shoulder 44 of arm 31 and thelower face of the boss 42.l j y From the foregoing description, it willbe evi'- dent that my improved arrangement for mounting the door of theenclosed cutout on the fuse holder makes it possible to adequatelyprotect the parts of the cutout from all sorts oi.'r adverse weatherconditions and at the same time protects do so, the details of theinvention may be sultu ably modiiied for' incorporation in other formsof fuse cutouts without departing from the true spirit and scope of theinvention as dened in the appended claims. Y

yWhat I claim as new and desire to secure by Letters Patent of theUnited States is:

1. In an electric cutout, the combination of a housing having an openingin a side thereof and having a movable door for closing the opening toprotect the interior of the housing from adverse weather conditions, anexpulsion fuse unit mount` edv and electrically connected within thehousing,

' and means supporting the door on said fuse unit vfili with the rim ofthe door in closely cooperative substantially weathertightrelation withrespect to the rim of said opening and'operative upon recoil of the fuseunit incident to fuse operation for minimizing the transmission of shockthrough the door to the rim of the housing opening.

2. In an electric cutout, the combination of a housing having anopening, in a side thereof, a door for closing the opening to protectAthe in'- terior of the housing from adverse weather conditions, anexpulsion fuse unit mounted and electrically connected within thehousing,`means for supporting the door on the fuse unit with the rim ofthe door in relatively close relation to the rim of the housing, andshock absorbing means operative to minimize the transmission of therecoil force from the fuse unit to the door upon operation o! the fuseunit.'

3. In an electric cutout, the combination of a housing having an openingin a side thereof, an expulsion fuse unit, means for mounting andelectrically connecting the fuse unit within the housing, a door forclosing said opening to protect the interior of the housing fromvadverse weather conditions, and means for movably mounting the door onthe fuse unit with the rim of the door in cooperative weathertightrelation with respect to the rim of said opening including a shockabsorbing device operatively connected between the door and fuse unitvfor minimizing the transmission to the door of the recoil force of thefuse unit incident to fuse operation to thereby prevent damaging impactof the door against the rim of the housing opening.

4. In an electric cutout, the' combination of a housing having anopen-side, a door for closing said open side, an expulsion fuse unitmounted and electrically connected in lthe housing,

means for supporting the door on the fuse unit with the rim of the doorin relatively close engagement with the rim of said open side of thehousing, and shock absorbing meansl operative to prevent damaging impactof the door rim against the rim of the housing upon recoil of the fuseunit incident to fuse operation.

' 5. In an electric cutout, the combination of a housing having an openside and a flanged recess extending around the rim of the top and atleast a portion of the sides of said open side, an expulsion fuse unitmounted and electrically connected in the housing and having adownwardly directed gas discharge opening, a door arranged to seat insaid flanged recess to close the opening, and means for supporting thedoor on the fuse unit operative normally for maintaining the top edge ofthe door substantially in engagement with the top wall of said ilangedrecess and operative upon recoil'of the fuse unit incident to fuseoperation for preventing damaging impact of the door against said topwall ot the iianged recess.

6. In an enclosed fuse cutout, the combination of a housing having anopening in a side thereof, spaced contacts mounted in the housing, anexpulsion fuse unit, means for supporting the fuse unit in the housingconnected between the contacts, a door, means for mounting the doorslidably on fuse unit in position to close said opening when the fuseunit is in connected position, a boss rigidly carried by the door, asecond boss rigidly carried by the fuse unit and a. spring operativelyconnected between said two bosses for the transmission to the door ofthe recoil of the iuse unit upon fuse operation.

7. In an electric cutout, the combination of a housing having an openside, an expulsion fuse unit mounted and electrically connected withinthe housing, a door for closing said open side, means for motuiting thedooron the fuse unit including bosses carried by the door and havingopenings for the relatively loose slidable accommodation of the fuseunit, means providing an abutment rigidly carried by the door, meanspro-l viding an abutment rigidly'carried. by the fuse unit and a springoperatively disposed between said abutments for maintaining the top ofsaid door in relatively close engagement with the top Vsaid housingopening, means for siidably mounting the door on the fuse unit with therim of the door seated'in said ilanged recess of the housing, and springmeans operatively connected between the door and fuse' unit formaintaining the top of the door in substantially weathertight relationwith respect to the top portion of said flanged recess, said springbeing operative also upon recoil of the fuse -unit incident to fuse.operation for absorbing at least part fof the force of such recoil andpreventing damaging impact between the top of the door and the housing.

9. In an electric cutout, the combination of spaced contacts, anexpulsion fuse unit, means for supporting the fuse unit connectedbetween the contacts, and an inertia element movably and resilientlymounted on the fuse unit for absorbing at least part of the shock of thefuse unit recoil incident to fuse operation to thereby minimize thestrain to which said supporting means is subjected due to such recoil.

10. In an electric cutout, the combination of spaced contacts, anexpulsion fuse unit, means for connecting the fuse unit between thecontacts, means for supporting the fuse unit removably in a connectedposition, an element mounted slidably on the fuse unit and a springconnected between said element and the fuse unit to provide a cushioningaction therebetween upon recoil of the fuse unit incident to fuseoperation, said element having suiiicient inertia upon recoil of thefuse unit to cause said spring to act as a shock absorber to relievesaid lfuse supporting means of a portion of the shock of such recoil.

. RALPH s. BENNETT.

